False Start

Definition

It is a False Start if the ball has been placed ready for play, and, prior to the snap, an
offensive player who has assumed a set position charges or moves in such a way as to simulate the start of a play, or if an offensive player who is in motion makes a sudden movement toward the line of scrimmage. Any quick abrupt movement by a single offensive player, or by several offensive players in unison, which simulates the start of the snap, is a false start. Exceptions: This does not apply to an offensive player under the center who turns his head or shoulders, unless
the movement is an obvious attempt to draw an opponent offside.

Outcome

Loss of five yards from the line of scrimmage. The foul is enforced prior
to the snap.